The present invention generally relates to an improved nutcracking unit for use in a high production nutcracking apparatus.
In applicant""s prior U.S. Pat. Nos. 5,623,867 and 6,205,915, there is disclosed a high production nutcracking apparatus wherein a plurality of cracking units are arranged on a rotatable turret, with each cracking unit having an opening adapted to receive an individual nut which is removed from a feed conveyor as the cracking unit moves through a pickup position. Each cracking unit includes an anvil mounted on one side of the opening, and a cracking die mounted for limited movement on the other side of the opening and so that the anvil and cracking die are adapted to receive and hold the nut therebetween. A free floating shuttle is mounted rearwardly of the die, and the shuttle is thrust forwardly into impacting engagement with the rearward side of the cracking die after the nut is receive in the opening, and so that the shell of the retained nut will be cracked by the resulting forward movement of the die.
The above patents and applicant""s further U.S. Pat. No. 6,182,562 disclose a cracking die and anvil which are configured so as to include opposing end faces which are of conical configuration for partially receiving the opposite ends of the nuts which are held therebetween.
During the processing of relatively small nuts which commonly have pointed ends, such as pecan seedlings, the impact of the cracking force will be imparted directly on the pointed end of the nut by the conical surfaces, rather than on the side walls of the nut. As a result, the impact force will crush the pointed ends of the nuts, but leave much of the remainder of the shells attached to the meat of the nut, and a high percentage of the nuts have attached shell fragments which remain attached even after the nuts are subsequently processed in conventional shelling and air separation machines.
It is accordingly an object of the present invention to provide an improved nutcracking apparatus of the described type which is able to efficiently process relatively small nuts, such as pecan seedlings.
The above and other objects and advantages of the invention are achieved by the provision of a nutcracking unit of the described type which is adapted to efficiently crack relatively small nuts such as pecan seedlings which have pointed ends, and wherein the cracking die and anvil have opposing concave cracking surfaces for receiving an end portion of the nut therein and which are configured in such a way that the cracking impact force is applied about an annular circle which is axially spaced from the pointed end of the nut. This in turn causes the formation of relatively small end caps at the opposite ends of the nut which are broken and easily separated, thereby facilitating the separation of the meat of the nut from the shell, either in the cracking unit or in the downstream shelling and air separation machines. The percentage of partially or insufficiently cracked nuts is thus reduced.
To achieve this result, the configuration of the concave cracking surfaces of both the cracking die and anvil are defined by non linear, side walls when viewed in cross section which are adapted to engage the received nut at a location axially spaced a relatively short distance from the pointed end of the nut. In a preferred embodiment, the side walls are defined by an outwardly bowed convoluted curve made with circle arcs when viewed in cross section. Also, the bottom end portion of the concave cracking surface is defined by an arc of a circle when viewed in cross section, with the arc having a radius of at least about {fraction (1/16)} inch.
With the above configuration, the pointed end of the nut may be received in the concave end portion of either or both the anvil and the cracking die, with the pointed end of the nut spaced from the bottom end portion and adjacent walls of the concave cracking surface. The impact force is thus removed from the pointed end of the nut, and moved axially so as to be imparted along an annular circle surrounding and spaced from the end of the nut as described above.